A Road-based QoS-aware Multipath Routing for Urban Vehicular Ad Hoc Networks

1. A Road-based QoS-aware Multipath Routing for Urban Vehicular Ad Hoc Networks Yi-Ling Hsieh and Kuochen Wang Department of Computer Science National Chiao Tung University To appear in GLOBECOM 2012

2. Outline • Introduction • Related work • Proposed road-based QoS-aware multipath routing protocol for urban VANETs (RMRV) • Multiple road-disjoint paths discovery • Path life time and life periods prediction • Dynamic QoS path switching • Simulation • Conclusion • References

3. Introduction – Motivation • Stable and efficient routing plays a key role for the success of VANETs • Road-based QoS-aware routing has been shown well-suited in urban VANETs [5][8] • (better than traditional node-based routing) • Multipath routing provides alternative routes once the current route fails However, existing multipath routing protocols are node-based, which are not suitable for urban VANETs

4. Introduction – Multipath routing • Multipath routing • further enhance the route stability • provides alternative routes once the current route fails • provides concurrent transmission with multiple paths (optional) • Existing multipath routing protocols • are node-based (not road-based) • potential drawback: potential transmission interference if they are multiple paths through the same road sections [14]  disjoint paths discovery

5. Introduction – QoS routing • QoS routing in urban VANETs • Utilize probability of connectivity and hop count to decide the best QoS path • derive/estimate probability of connectivity and hop count with vehicles mobility data (e.g. speed, position, node density) • Most of current QoS routing protocols for VANETs are node-based • derive a route’s QoS along with route discovery • only consider straight roads (e.g. highways) or limited local roads • due to inherited weakness of node-based routing For generic city road topologies, road-based routing approach is preferred • Road-based QoS routing • IGRP [5]: directly determine a path’s with the assistance of traffic statistics • Additional traffic statistics is required; however, it may not reflect the current situation

6. Introduction – the proposed routing protocol • We propose a road-based QoS-aware multipath routing protocol for urban VANETs (RMRV) • RMRV can find multiple road-disjoint paths • Predict a path’sfuture lifetime and life periods to adaptively utilize multiple paths • We propose a space-time planar approach to predict the connectivity of each road section in a path • Dynamic QoS path switching • dynamically switch to a path that satisfies the packet delay constraint • Packet delay is estimated according to a path’s life periods

7. Related work

8. Proposed road-based QoS-aware multipath routing protocol for urban VANETs (RMRV) • Problem description • How to find multiple road-disjoint paths? • Among the multiple paths, we choose the path with longest lifetime How to estimate a road section’s lifetimeso as to derive a path’s lifetime • As time elapses, a road section becomes connected or disconnected  How to dynamically switch to another path

9. Proposed RMRV – multipath discovery • Multipath discovery (route discovery, RD) • RD packet: [src, dest, seq #, road section list (RS list)] • generated at source and being flooded out, until reaching destination • The RS list in an RD packet is updated when the packet enters a new road section • RD packet table • Every node maintains one, to check whether a received RD packet had been seen • Road-disjoint paths • RD packet with duplicate RS is dropped • (disregarding the beginning and ending RSs) • However, duplicate RSs are allowed if not enough multiple paths are available • Loop detection • e.g. a node in RS3 received an RD packet with RS list [5, 3, 2, 7, 8]

11. Proposed RMRV – multipath discovery • Route reply • For each RD packet, the destination node sends a route reply (RR) packet to the source node • Along with the RR packet being relayed among RSs, the path’s future connectivity prediction is processed in each RS

12. Road section connectivity problem • Geographical forwarding • used to relay data packets through a road section • Every node maintains a neighbor table for choosing next hop • neighbor table: every node periodically broadcast a HELLO

13. Road section connectivity problem • A potential problem and its solution • As time elapses, a road section may become connected or disconnected, due to node mobility • RS life periods prediction path life periods path switching before disconnection

14. Road section connectivity problem – space-time planar approach We propose a space-time planar approach to formulate and resolvethe road section connectivity problem • A road section’s life period can be derived  A path’s life period is then derived

16. Path lifetime estimation and QoS path switching • RS life periods is included in the RR packet • RR packet piggybacks the relay nodes’ neighbor tables • The last node in the RS, e.g. node i, calculates RS C1-C2’s life periods using the space-time planar approach • Intersect the derived life periods with the existing life periods piggybacked in the RR packet (so as to reduce RR packet size) • The piggybacked neighbor tables are also removed

17. QoS path switching • The source node may switch to a path which is connected currently or satisfies delay constraint • Small gaps may be tolerated because of using carry-and-forward

18. QoS path switching • Packet delay di for path i is due to two kinds of delay • Transmission delay (dp) • Path disconnection delay (dd) • di = dp(i) + dd(i)

19. QoS path switching • Transmission delay (dp) • dij : packet delay through RSij, dij = tp*{2+[(Lij – 2*s)/(Tr/2)]} • tpis transmission delay of a hop, which is regarded as a constant [8] • dp(i) = ∑dij, for RSij in path i • Path disconnection delay (dd) • dd is the sum of the mean of each disconnection period 19

20. Simulation • Simulator: QualNet 5.0 • Map: a grid map of 1000m x 1000m with 200m interval [8] • Total 200 nodes • Node mobility trace generator: VanetMobiSim • node speed: [0m/s, 20m/s] • Radio range: 275m [8] • Two-ray ground propagation model [8] • With NLOS, only nodes in adjacent road sections are allowed for radio communication. The upper bound distance is set to 80m • CBR • 10 packets/s • Packet size: 512 bytes • 2 ~ 10 concurrent CBR connections

21. Simulation

22. Simulation

23. Simulation

24. Conclusion • We have presented a road-based QoS-aware multipath routing protocol for urban VANETs (RMRV). • To the best of our knowledge, there is no existing road-based multipath routing protocol for VANETs. • The proposed RMRV is used to find multiple paths and to estimate paths’ future life periods for QoS path switching. • A space-time planar graph approach has been proposed to predict the connectivity of each road section in a path, and thus a path’s future lifetime and life periods can be derived.

25. Conclusion • Simulation results have shown that the proposed RMRV has 12.2% higher packet delivery ratio, shorter 11.5% average end-to-end delay and 34.3% lower control overhead than those of RBVT-R. • The proposed RMRV is very suited to high mobility urban VANETs.

26. References • M. K. Marina and S. R. Das, "Ad hoc on-demand multipath distance vector routing," Wireless Communications and Mobile Computing, pp. 969-988, 2006. • Cheng-Shiun Wu, Shuo-Cheng Hu and Chih-Shun Hsu” Design of fast restoration multipath routing in VANETs", in Proc. of Computer Symposium (ICS), pp. 73 - 78, 2011. • S.-J. Lee, M. Gerla,"Split Multipath Routing with Maximally Disjoint Paths in Ad Hoc Networks," IEEE International Conference on Communications, vol. 10, pp. 3201 - 3205, 2001. • X. Huang and Y. Fang, "Performance Study of Node-Disjoint Multipath Routing in Vehicular Ad Hoc Networks," vol. 58, issue 4, pp. 1942 - 1950, 2009.

27. References • H. Saleet et al., "Intersection-based geographical routing protocol for VANETs: a proposal and analysis," IEEE Transactions on Vehicular Technology, vol. 60, issue 9, pp. 4560 - 4574, Nov. 2011. • M. Jerbi, S.-M. Senouci, R. Meraihi and Y. Ghamri-Doudane, "An improved vehicular ad hoc routing protocol for city environments," in Proc. of IEEE International Conference on Communications (ICC), pp. 3972 - 3979, 2007. • K. Lee, M. Le, J. Haerri and M. Gerla, "Louvre: Landmark overlays for urban vehicular routing environments," in Proc. of IEEE VTC, pp. 1-5, 2008. • J. Nzouonta et al., "VANET routing on city roads using real-time vehicular traffic information," IEEE Transactions on Vehicular Technology, vol. 58, issue 7, pp. 3609 - 3626, 2009.

28. References • H. Rongxi ,H. Rutagemwa and S. Xuemin, "Differentiated reliable routing in hybrid vehicular ad-hoc networks," in Proc. of International Conference on Communications, pp. 2353-2358, May 2008. • Cheng-Shiun Wu, Shuo-Cheng Hu and Chih-Shun Hsu” Design of fast restoration multipath routing in VANETs", in Proc. of Computer Symposium (ICS), pp. 73 - 78, 2011. • S. Bitam and A. Mellouk, "QoS swarm bee routing protocol for vehicular ad hoc networks," in Proc. of International Conference on Communications (ICC), pp. 1-5, June 2011. • Z. Mo, H. Zhu, K. Makki and N. Pissinou, "MURU: A multi-hop routing protocol for urban vehicular ad hoc networks," in Proc. of 3rd Annual International Conference on Mobile and Ubiquitous Systems, 2006, pp. 1–8, 2006.

29. References • Y. Gongjun, D.B. Rawat and B.B. Bista, "Provisioning vehicular ad hoc networks with quality of service," in Proc. of International Conference on Broadband, Wireless Computing, Communication and Applications(BWCCA), pp. 102 - 107, 2010. • Yufeng Chen, Zhengtao Xiang, Wei Jian and Weirong Jiang, "An Adaptive Cross-Layer Multi-Path Routing Protocol for Urban VANET," in Proc. of the IEEE International Conference on Automation and Logistics, pp. 603 – 608, 2010. • Xiaoxia Huang and Yuguang Fang, "Performance Study of Node-Disjoint Multipath Routing in Vehicular Ad Hoc Networks," IEEE Transactions on Vehicular Technology, vol. 54, issue 4, pp. 1942 - 1950, 2009. • Yi-Ling Hsieh and Kuochen Wang, “Road Layout Adaptive Overlay Multicast for Urban Vehicular Ad Hoc Networks,” in Proc. of the IEEE 73rd VTC, pp. 1-5, 2011. (submitted to journal Computer Networks)